Installing comp/FH . . . does amount of torque affect accuracy?

**cdb** · 10-27-20, 11:17

Originally Posted by gaijin

Well the barrel ID isn't going to "spring back" to original ID dimension. It's steel.

That depends on whether the strain exceeded the elastic deformation limit of the material.

**Disciple** · 10-27-20, 12:55

Originally Posted by gaijin

The barrel muzzle threads are not 90 degree to bore/barrel, but are angled to allow MD to be twisted onto barrel- to contact washer and tighten MD to barrel.

Why wouldn't the threads be cut square to the bore? Are you describing a tapered thread?

**gaijin** · 10-27-20, 13:33

Look at threads.

If you screw a MD on barrel, sans washer, and watch MD under mag you’ll see it contacts barrel shoulder in one area first.
I’m a lousy described, but that’s how threads work.
If threads were perfectly square to bore they’d be concentric rings, the MD would just spin, not tighten.

**markm** · 10-27-20, 13:37

Interesting Ned data. I avoid excessive torque anyways, but that's quite impressive.

**1_click_off** · 10-27-20, 14:49

I see stopping at 20lbs on a flash hider/brake, what about a suppressor mount? You go any further for it or just rocksett and 20lbs?

**556Cliff** · 10-27-20, 15:30

Originally Posted by Ned Christiansen

The only one I tested was one of many I had around that looked the same. Not surprised that JP came up with a solution, dang smart people there, and I'll check it and the Armageddon too. Not promising a test but let's see if I can make it happen.

I'd love to see it if it's something you could ever get around to. It would be very interesting to see if those two different designs actually work as advertised.

I've had mixed experiences with standard crush washers. Some don't seem to want to actually crush with any reasonable amount of torque and others seem to crush much closer to the 15-20 foot pound torque spec... At least somewhere under 30 foot pounds just guessing.

**1168** · 10-27-20, 15:55

Is all of this true with no washer at all, like an un-timed suppressor mount?

**mpom** · 10-27-20, 16:57

Old time Service Rifle smiths such as Compass Lake Engineering or White Oak have known for decades that excessive torque on muzzle devices negatively affected accuracy, why they usually tighten to 10-15 foot pounds and sometimes use a non permanent lock tite to prevent loosening. Suspect its also true if no washer is used, as stress is ultimately transmitted via threads to the barrel.

Mark